1. Field of Invention
The invention relates to powered devices for taking and retrieving samples of fluid from any depth, level, or place within a body of fluid.
2. Description of the Prior Art
The prior art discloses many devices for taking samples of fluid at various depths and levels and usually provided with valve means that are manually or mechanically activated. A known electric sampling device is disclosed in U.S. Pat. No. 4,347,751 and comprises an exposed and unprotected system of pulleys or sprockets connected by belts or chains to a battery operated motor to open and close a pair of ball valves at opposite ends of a tubular body.
Another electrically controlled sampling device for taking samples at predetermined depths in a sea is disclosed in U.S. Pat. No. 3,625,066 and comprises a standard Nansen bottle with a pair of valves at its opposite ends connected to a slide rod and latches which are maintained in a latched position and movable under the influence of elastic bands. A surface powered low wattage resistor is connected to and retains the latches in a latched position to maintain valves open during its decent into the sea. At the desired depth the resistor is energized to release the latch and allow the elastic bands to act upon the rod and close the valves.
One disadvantage of the prior art devices is that the mechanism for operating the sampler are more complicated and mounted on the exterior of the main container and therefor exposed to and not protected from corrosive and toxic fluids. Another disadvantage of prior devices is that when the standard bailer is lowered into the fluid body every increment of its depth passes therethrough. In effect, the device is contaminated by the full volume of the body of fluid or liquid being sampled. If a small quantity (PPM or PPB) of a substance is later detected in the sample, it is not known whether it came from the lowest depth to which the device was lowered or from some intermediate depth.
The Applicants' device hereinafter disclosed is a true point-source device in that it can be lowered to any predetermined depth without entrance of fluid until it reaches the desired depth. At this depth an electric or fluid powered means is energized to open an inlet valve and allow the device to fill and air to vent. After a short period, the device is filled and the power means is reversed to close the inlet valve and seal a true representative uncontaminated sample of the fluid at the depth it was taken. Thus, the sample is sealed in the bailer and raised to the surface for analysis.